载人登月舱动力下降段应急返回轨道设计

Exploring Abort of Manned Lunar Module from Powered Descent Phase

文章主要研究载人登月舱动力下降段应急返回轨道设计问题。针对应急返回对等待时间的需求,改进了同心椭圆返回轨道方案。将显式制导法应用于应急返回上升段控制中,充分利用了登月舱的剩余速度,得到了满足要求的入轨精度。根据仿真结果确定了利用下降级推力器完成上升段应急返回的准则。在上升段仿真的基础上设计了跟踪段过渡椭圆轨道,显著缩短了登月舱在停泊轨道的等待时间。文中的方法和结论可以为载人登月工程应急返回提供一定的参考价值。

Sections 1, 4, present the results lyzed the results. The 2 and 3 explain the of our exploration, u exploration mentioned in the title. Tables 2, 4 and 5, and Figs. 1 and tilizing the published parameters of the Apollo 17; in addition, we anacore of sections 1,2 and lunar module abort from powered descent phase. aborting 3 consists of： ＂We mainly focus on the orbit design of the manned Firstly, in order to meet the requirements of the manned spacecraft , an improved co-elliptic technique was proposed. Secondly, the expression of the explicit guidance law for ascent phase in abort was deduced. Then, with the help of Simulink tools this guidance law was proved to be precise enough when used in ascent phase, for the error in the height could be neglected and the error in the velocity was within a few meters per second. Finally, the height of apolune of the ellipse transfer orbit was designed based on the result of the ascent phase, which effectively shortened the waiting time of lunar module. Only abort from the pre-phase of powered descent needs this technique. ＂ may be useful for the manned lunar project. Section 4 presents our preliminary main conclusions, which